What Factors are Associated With Conversion to Knee Arthroplasty After Subchondroplasty?

BACKGROUND: Subchondral bone marrow lesions identified on knee MRI are believed to play a role in osteoarthritis-associated pain. The subchondroplasty procedure is an arthroscopically assisted procedure for treating such lesions to avoid larger procedures such as knee arthroplasty. However, the survivorship free of conversion to arthroplasty and the factors associated with an increased likelihood of conversion of subchondroplasty to arthroplasty have not been well defined. QUESTIONS/PURPOSES: We performed this study to (1) determine the 5-year survivorship of subchondroplasty free from conversion to knee arthroplasty (unicompartmental or total) and (2) identify variables that were associated with progression to knee arthroplasty after a subchondroplasty procedure. METHODS: In all, 216 patients who underwent a subchondroplasty procedure performed by one surgeon with subchondroplasty experience at a single-center, multilocation facility between September 2014 and August 2017 were retrospectively evaluated to estimate survivorship free from conversion to knee arthroplasty at 5 years. The mean ± SD age and BMI at the time of subchondroplasty procedure were 59 ± 11 years and 33 ± 8 kg/m 2 , respectively; 60% (129 of 216) of the patients were women. Other variables collected were smoking status and grade and location of chondral lesions. The electronic medical record was reviewed to determine whether the patient had a knee arthroplasty after subchondroplasty. Survivorship free from conversion to knee arthroplasty at 5 years was calculated from a Kaplan-Meier survivorship estimator. Factors associated with progression to knee arthroplasty were examined using t-tests and chi-square analyses. Variables showing evidence of an association with knee arthroplasty were explored further using a Kaplan-Meier survivorship estimator (n = 190). RESULTS: Kaplan-Meier survivorship free from conversion to knee arthroplasty was 73% (95% CI 67% to 79%) at 5 years after subchondroplasty. We found that age older than 50 years and Grade 4 chondral lesions were associated with conversion to knee arthroplasty. Patients with a Grade 4 chondral lesion had 5-year survivorship of 62% (95% CI 54% to 71%) and 59% (95% CI 50% to 69%) for those older than 50 years with a Grade 4 chondral lesion. CONCLUSION: Currently, we recommend a detailed, informed discussion of the risks versus benefits with patients who are considering a subchondroplasty procedure, particularly patients aged 50 years and older and those with Grade 4 chondral lesions. Future randomized trials, including those that compare the subchondroplasty procedure with arthroscopy alone or nonoperative management options, are still needed to confirm the efficacy and role of the subchondroplasty procedure in patients with knee osteoarthritis, because only such prospective studies can determine the success of the procedure. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Robotic-assisted total knee arthroplasty: Is there a maximum level of efficiency for the operating surgeon?

Aims: Recent studies have attempted to quantify the learning curve associated with integration of robotic technology into surgical practice, but to our knowledge, no study has demonstrated the number of cases needed to reach a steady state of maximum efficiency in operating times using robotic assisted technology. Patients and methods: This was a retrospective analysis of 682 consecutive knees that underwent a robotic-assisted TKA for osteoarthritis by a single surgeon between 2017 and 2020. Procedure times (minutes), length of stay (LOS), and short-term postoperative complications and reoperations were analyzed to define trends. Time series analyses were used to identify the approximate time-point at which a maximum level of surgical operating speed was achieved. Analysis of Variance (ANOVA) and chi-square analyses then followed to compare average procedure duration, LOS, and complications across distinct moving groups of 50 procedures. Results: Time series analyses suggest substantially improved times by the 50th procedure and reached a stable plateau between the 150th and 200th procedure. Average duration for the first 50 procedures was approximately 85 min, dropping to 69 min for procedures 51-100, 66 min for procedures 101-150, and then plateauing at approximately 61 min for procedures 151-682, demonstrating significant improvements in surgical efficiency at each 50-procedure interval (p < 0.05). There was no significant difference in LOS, readmissions, and reoperations with increasing groups of 50 procedures performed. Conclusion: Results from this study will allow surgeons to better understand the implications of integrating robotic arm-assisted technology into their practice. Surgeons can expect significant improvement of their operative time following completion of at least 50 procedures, while likely reaching a maximum level of surgical efficiency between 151 and 200 procedures.

Occupational Hazards for the Practicing Orthopaedic Surgeon: A Standard Review.

LEVEL OF EVIDENCE: Level V.

Posterior approach shoulder arthroplasty: a cadaveric study assessing access.

BACKGROUND: Posterior shoulder arthroplasty is an approach to shoulder replacement. The goal of this cadaveric study was to determine anatomic feasibility for posterior approach shoulder arthroplasty by evaluating access to the glenoid, humerus, and canal. METHODS: Twelve fresh frozen shoulders (10 males; 2 females) (mean age, 76 [range, 55-92 years]; weight, 79 kg [range, 34-125 kg]) were used. Traditional exposure techniques and retractors were used to evaluate direct access. Exposure to the glenoid and humerus was evaluated using digital imaging software. Successful placement from stemmed arthroplasty was evaluated using digital radiographs and imaging software. RESULTS: The posterior approach permitted direct access to 88.8% ± 8.1% of the glenoid. There was access to the center of the humeral head cut surface in 12 of 12 specimens. In 10 specimens, there was 100% access to the entire cut surface of the humerus and peripheral edges. The average access to the humerus was 95.3% ± 13.4%. Average angulation with stem placement was 0.73° of varus (range, 4.4° of varus to 3.5° of valgus). Regarding lateral plane angulation, there was an average of 0.33° of posterior angulation (range, 3.3° of posterior angulation to 2.5° of anterior angulation). CONCLUSION: Access to the center of the glenoid and humerus was achieved in all cases. More research is needed to evaluate the clinical efficacy of posterior shoulder arthroplasty, including mid- and long-term outcome and safety studies.

Improving Orthopedic Patient Outcomes: A Model to Predict 30-Day and 90-Day Readmission Rates Following Total Joint Arthroplasty.

BACKGROUND: Over the next 10-15 years, there is expected to be an exponential increase in the number of total joint arthroplasties in the American population. This, combined with rising costs of total joint arthroplasty and more recent changes to the reimbursement payment models, increases the demand to perform quality, cost-effective total joint arthroplasties. The purpose of this study is to build models that could be used to estimate the 30-day and 90-day readmission rates for patients undergoing total joint arthroplasty. METHODS: A retrospective review of patients admitted to a single hospital, over the course of 56 months, for total joint arthroplasty was performed. The goal is to identify patients with readmission in a 30-day or 90-day period following discharge from the hospital. Binary logistic regression was used to build predictive models that estimate the likelihood of readmission based on a patient's risk factors. RESULTS: Of 5732 patients identified for this study, 237 were readmitted within 30 days, while 547 were readmitted within 90 days. Age, body mass index, gender, discharge disposition, occurrence of cardiac dysrhythmias and heart failure, emergency department visits, psychiatric diagnoses, and medication counts were all found to be associated with 30-day admission rates. Similar associations were found at 90 days, with the exclusion of age and psychiatric drug use, and the inclusion of intravenous drug abuse, narcotic medications, and total joint arthroplasty within 12 months. CONCLUSION: There are patient variables, or risk factors, that serve to predict the likelihood of readmission following total joint arthroplasty.